Focusing on the niche field of metal ion toxicity in Quantitative Structure Activity Relationships (QSAR), this text concentrates on the basic and essential applications of QSAR methods in metal ions for readers already familiar with the field and statistics. It delineates the theoretical basis and provides a concrete introduction to studying the biological activity and toxicity of metal ions as they impact health and the environment. The book describes the applications of QSARs in characterizing the biological activity and toxicity of metal ions and provide parameters for the correlation of structure with inorganic biological activity. It includes a CD-ROM with approximately 100 references on QSARs for metal ions.